KR20230070537A - Apparatus and method for extracting energy from a fluid - Google Patents

Abstract

An apparatus and method for extracting energy from a vibrating working fluid such as blue is disclosed. The device 10 includes a flow path 40 for a working fluid, a turbine 44 and a flow control device 38, each of the turbine 44 and flow control device 38 directly connected to the flow path 40. In fluid communication, and in use herein, the flow control device 38 comprises a first configuration in which the flow control device 38 is opened to allow a flow of a working fluid, such as air, to exit the flow path 40 through the flow control device. The flow control device 38 is selectively moveable between a second configuration that restricts the flow of working fluid through the flow control device. In this example, the working fluid must then enter the flow path 40 through the turbine 44 where it can be used to generate electricity.

Description

APPARATUS AND METHOD FOR EXTRACTING ENERGY FROM A FLUID

The present invention relates generally to energy generation, and in particular, but not exclusively, to energy generation using a wave energy extraction system. The present invention relates to the design of devices as well as methods for optimizing the capture of energy from such devices.

Many types of wave power systems have been proposed in the art. These systems are based on the principle of generating electricity by using the movement of waves to cause rotational motion of a turbine and drive a generator. Known wave power systems use one or more fluid flow ducts to house oscillating water columns (OWCs) connected to turbines. In such systems, as a result of the oscillatory motion of the waves within the OWC caused by the inward and outward directed wave flow, there is frequently an airflow condition reversal caused by the displacement of air within the duct. These turbines often have the disadvantages of being complex in construction, expensive to manufacture, and unable to withstand harsh environmental conditions (salt water, high or rough seas resulting in large or unpredictable forces) over long periods of time. Many of these conventional systems operate at low efficiencies due to losses in converting the motion of the OWC into rotating mechanical energy in a bidirectional turbine.

There is a need for improved system designs that can capture energy from OWCs in an efficient manner and lower the cost of doing this.

In a first aspect, an embodiment of a device for extracting energy from a vibrating working fluid is disclosed, the device comprising a flow path for a working fluid, a turbine in direct fluid communication with the flow path, and a flow control device, respectively, wherein, in use, , The flow control device has a first configuration in which the flow control device is opened to allow the flow of the working fluid to exit the flow path through the flow control device, and the flow control device restricts the flow of the working fluid through the flow control device so that the working fluid It is selectively movable between the second configuration entering the flow path through the turbine.

In certain embodiments, the flow control device changes the configuration of access to the flow path in response to changes in pressure and/or flow direction of the vibrating working fluid.

In certain embodiments, the flow control device is completely closable to facilitate the flow of working fluid only through the turbine in the second configuration.

In certain embodiments, the flow control device is equipped with a control mechanism to control its movement between the first configuration and the second configuration. In one form thereof, the flow control device has an element that is movable by a control mechanism to open and close to the flow of a working fluid. In its particular form, the element is either hinged, slidably or rotatably movable and shaped to cover the cross-sectional open passage of the flow control device.

In certain embodiments, the flow control device is either a butterfly valve or a check valve.

In certain embodiments, a turbine includes a rotor including a central hub and a plurality of blades arranged around and extending from the periphery of the hub, the rotor being disposed in a housing connected to a flow path, whereby the shape of the blades and the hub Its orientation with respect to s facilitates one-way rotation of the turbine rotor in response to a one-way, axial flow of working fluid through the housing. In one form thereof, the generator is configured for rotation by a turbine to produce electrical energy. In one particular embodiment, the drive shaft is connected at its proximal end to a hub and at its distal end to a generator.

In certain embodiments, the working fluid is air, and the flow of air is created by vibration of a frequency column located in the duct and in fluid communication with the flow path.

In certain embodiments, the duct (a) is arranged such that, in use, it is substantially submerged below the mean surface level (MSL) of the body of water in which the duct is positioned, and has an opening arranged to receive surf from the body of water. (b) a second portion suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from the surf after the wave has flowed through the first portion; , the flow path is defined by the area of the second portion extending above the maximum level of water received from the surf after the wave has flowed through the first portion.

In one form thereof, the first and second parts of the duct are connected via a flow direction control segment intermediate the first and second parts, the flow direction control segment being arranged at the junction of the first and second parts and the first and a planar inclined portion extending between the second portion.

In one particular embodiment, the first and second portions of the duct are generally elongate conduits, the first portion having a greater cross-sectional area than the second portion. In one form thereof, the cross-sectional area at the opening of the first portion is a greater cross-sectional area than the rest of the first portion, and the conduit is provided outside the entry mouse area at the opening to accelerate the flow of the surf from the basin to the conduit. The cross-sectional area decreases when moving in a direction from to the second part. In one particular embodiment, in order to catch the larger flow of the surf from the body of water into the duct, the outer entry mouth area of the first portion is arranged to, in use, extend above the MSL of the body of water in which the duct is located.

In certain embodiments, the duct is operable to lie on the seabed of the body of water in which the duct is placed.

In a second aspect, an embodiment of a wave energy extraction system is disclosed, the system comprising: (a) for receiving a frequency column, wherein (i) in use is substantially submerged below the Mean Water Level (MSL) of the body of water in which the duct is located; (ii) a first portion suspended from the first portion and arranged to extend above the MSL when in use, wherein the first portion is suspended from the first portion and has openings arranged to receive incoming waves from the body of water, wherein the waves pass through the first portion; It includes a second part for receiving the water from the surf after flowing, so that in use the frequency column is built inside as a result of the repeated movement of the water in and out, and the flow of the water out is also through the opening, but pushed A duct formed in the direction opposite to the direction of the incoming wave; (b) a rotatable air turbine in direct fluid communication with a flow path located within the second portion of the duct; and (c) at least one flow control device also in direct fluid communication with the flow passage, wherein the flow control device, in use, causes a flow of displaced air to exit the flow passage when the device is opened and the frequency column is received into the second portion of the duct. The device is arranged to move between a first configuration allowing air to flow to the second section and a second configuration restricting air flow to the second section, so that as the frequency column flows out of the duct in the opposite direction, the flow of air is directed to a rotatable air turbine. is sucked back into the passage through the

In certain embodiments, the flow control device changes the configuration of access to the second portion in response to changes in pressure and/or flow direction of the vibrating working fluid.

In certain embodiments, the system further includes a generator configured for rotation by the turbine to generate electrical energy. In one form thereof, the turbine includes a rotor including a central hub and a plurality of blades arranged around and extending from the periphery of the hub, the rotor being disposed in a flow path connected to the second portion, whereby the shape and shape of the blades and Its orientation relative to the hub facilitates one-way rotation of the turbine rotor in response to axial airflow through the flow passage to the second portion. In one particular form thereof, the drive shaft is connected at its proximal end to a hub and at its distal end to a generator.

In certain embodiments, the frequency of the frequency column in use is determined by selective movement of the one or more flow control device(s) between the first and second configurations of the flow control device as a percentage of the surface area of the second portion extending over the MSL ( ) can be varied by changing the cross-sectional area of In one form thereof, the cross-sectional area of the flow control device(s) as a percentage of the surface area of the second portion extending over the MSL is set at less than 15%. In a particular form thereof, the proportion is set to be less than 10%.

In certain embodiments, the system of the second aspect includes an apparatus as defined in the first aspect.

In a third aspect, an embodiment of a method for controlling the frequency of movement of water within a frequency column to substantially correspond to the frequency of incoming and outgoing waves from a body of water in fluid communication with the frequency column is disclosed, the method comprising:

a. arranging a duct to receive a vibrating water column, wherein the duct is (i) arranged to be substantially submerged below the Mean Water Level (MSL) of a body of water in which it is located in use, and arranged to receive surging waves from the body of water. (ii) a first portion having an opening, and (ii) a second portion suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from the surf after the wave has flowed through the first portion. Thus, in use, a frequency column is built up in the duct as a result of the repeated movement of water into and out of the duct, and the flow of water out of the duct is also through the opening, but in a direction opposite to that of the surf; and

b. changing the configuration of at least one flow control device in direct fluid communication with the flow path inside the second portion of the duct extending over the MSL, wherein, when the device(s) are in use, the device is open so that the frequency wave flows into the duct. The device is arranged to move between a first configuration allowing flow of displacement air to exit the flow passage when received and a second configuration restricting air flowing through the device to the flow passage in the second portion, thus entering the duct and The frequency of the oscillation column flowing out of the duct substantially corresponds to the frequency of the incoming and outgoing waves from the body of water.

In certain embodiments, the method further includes using the control mechanism to continuously adjust the configuration of the at least one flow control device(s) in response to changes in the frequency of incoming and outgoing waves. In one aspect thereof, in use, the control mechanism selectively moves one or more of the flow control device(s) between a first configuration and a second configuration.

In certain embodiments, the duct, flow control device, and control mechanism of the third aspect are as defined in the first aspect.

In a fourth aspect, an embodiment of a duct for accommodating a frequency column is disclosed, the duct being arranged so as to (a) in use be substantially submerged below the mean water level (MSL) of the body of water in which the duct is positioned, and pushed away from the body of water. a first portion comprising a conduit having openings arranged to receive incoming waves, and (b) further comprising another conduit suspended from the first portion and arranged to extend above the MSL when in use, wherein the waves pass through the first portion. and a second part for receiving the water from the surf after flowing, wherein in order to catch the larger flow of the surf from the body of water to the duct, an entry mouse at the opening of the first part is used so that the duct is It is arranged to extend partially above the MSL of the body of water in which it is located.

In certain embodiments, the first portion has a larger cross-sectional area at the opening than the remainder of the first portion, and the conduit is provided at the entry mouse area at the opening to accelerate the flow of the surf from the watershed to the duct. The cross-sectional area decreases when moving in the direction towards the second part. In one form thereof, the uppermost and outermost regions of the entry mouse of the first portion are arranged to extend partially above the MSL of the body of water when in use. In one particular form, the top surface of the first portion slopes downward when moving in a direction from an entry mouse at the opening toward the second portion.

In certain embodiments, the duct of the fourth aspect is otherwise as defined in the first aspect.

In a fifth aspect, an embodiment of a device for extracting energy from a vibrating working fluid is disclosed, the device comprising: a housing defining a flow path for the working fluid; an energy conversion unit disposed in the housing and in fluid communication with a working fluid in the passage when in use; and flow control means in fluid communication with the flow path to selectively change the configuration of the flow path between an active configuration where, in use, the working fluid acts on the energy conversion unit and a bypass configuration where the working fluid bypasses the energy conversion unit. .

In a specific embodiment, the flow control means and the energy conversion unit are configured to operate continuously so that, in use, a flow of working fluid exits the flow path through the flow control means and a flow of working fluid enters the flow path through the energy conversion unit.

In a particular embodiment, the housing is arranged to receive a vibrating column located adjacent to the sea, and the direction of the working fluid acting on the energy conversion unit is related to the fall of the waves passing through it.

In certain embodiments, the energy conversion unit includes a turbine rotor.

In certain embodiments, the apparatus of the fifth aspect is otherwise as defined in the first aspect.

In certain embodiments, a sixth aspect discloses an embodiment of a method of extracting energy from a vibrating working fluid, the method comprising:

(i) positioning at least partially within a body of water having waves, a housing defining a flow path for receiving a vibratory working fluid;

(ii) arranging the energy conversion unit to be in fluid communication with the vibrational working fluid; and

(iii) selectively changing the configuration of the flow path between an active configuration in which the working fluid acts on the energy conversion unit when flowing in the first set direction and a bypass configuration in which the working fluid bypasses the energy conversion unit when flowing in the second direction; and providing a flow control means for

In certain embodiments, the method of the sixth aspect is otherwise as defined in the third aspect.

In a seventh aspect, an embodiment of a method for positioning an oscillating wave column energy capture device at an offshore location within a body of water is disclosed, the method comprising:

(i) positioning the device, which is itself equipped with a floating aid, on an operatively submersible floating platform;

(ii) allowing the platform and device to float on a body of water;

(iii) moving the platform and device to a set position within the body of water;

(iv) submerging the platform and thus separating it from the device, thereby leaving the device afloat in the body of water by means of the flotation aid; and

(v) thereafter removing the flotation aid so that the device may be partially submerged and placed on the seabed of a body of water at a set position for intended operational use of the device.

In certain embodiments, the energy capture device is otherwise as defined in the first or fifth aspect.

Throughout this summary and specification, the abbreviation MSL is used for “mean water level” or “mean sea level” and is defined as the midpoint between the mean low tide and the mean high tide within a body of water at a particular location. MSL thus means the average of the surface of a particular body of water and therefore also represents the vertical depth reference point from which wave crests or wave trough fluctuations can be measured.

Aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are part of the present invention and show the principles of any disclosed invention by way of example.

The accompanying drawings facilitate understanding of the various embodiments to be described.

1 is a schematic front perspective view of a device for extracting energy from a vibrating fluid, such as a wave from a body of water, according to a first embodiment of the present invention;
Fig. 2 is a schematic rear perspective view of the device according to Fig. 1;
FIG. 3a is a schematic partial cross-sectional side view of the device according to FIG. 1 as viewed along section AA perpendicular to MSL and at the beginning of wave movement towards the device; FIG.
Fig. 3b is a schematic partial cross-sectional side view of the device according to Fig. 1 as viewed along section AA perpendicular to MSL and from the point of view as the waves travel through the device and the gas flows out of the fluid control device(s) with displacement; .
3C is a view along section AA perpendicular to the MSL and as the waves move back out of the device towards the body of water and the fluid control device(s) are closed, gas is drawn into the flow through the one-way turbine to rotate the turbine and generate electricity. A schematic partial cross-sectional side view of the device according to FIG. 1 at the point of generating energy.
4 is a schematic front perspective view of a device for extracting energy from a vibrating fluid, such as a wave from a body of water, according to another embodiment of the present invention.
Fig. 5 is a schematic rear perspective view of the device according to Fig. 4, showing the lowermost inlet region and the wave-pierced lip of the interior of the oscillating wave column;
6 is a schematic partial cross-sectional side view of a device for extracting energy from a vibrating fluid, such as a wave from a body of water, according to another embodiment of the present invention; This figure shows the moment a wave travels through the device and the gas is displaced and flows out of the fluid control device(s) (inset photo, valve open).
Fig. 7 is a schematic partial cross-sectional side view of the device according to Fig. 6; The figure shows the moment when the waves move back out of the device towards the body of water, the fluid control device(s) are closed, and the gas is drawn into the flow through the one-way turbine to rotate the turbine and create electrical energy.
8 is a schematic front perspective view of a device for extracting energy from a vibrating fluid, such as a wave from a body of water, according to another embodiment of the present invention; The wave energy harvesting device is shown positioned on a submersible floating dock. When not submerged, the dock is movable by towing from behind the shipping vessel for underwater positioning of the device. The vibrating wave column device is itself equipped with a flotation aid.
Fig. 9 is a schematic front perspective view of the device for extracting energy according to Fig. 8, the device being positioned on the submersible floating dock shown in an unsubmerged position, now the device and the dock are on the side of a tugboat; It is shown being towed from the back of a shipping vessel of the type in the direction towards the intended destination of the device on the water.
Fig. 10 is a schematic front perspective view of the device for extracting energy according to Fig. 8, the device being shown now removed from the submersible floating dock; The dock is shown lowered in the water so that the device (floated by a flotation aid in the form of a buoy panel) can then be pulled forward and removed from the dock.
Fig. 11 is a schematic front perspective view of the device for extracting energy according to Fig. 8, the device now shown being detached from a submersible floating dock, the dock being now lifted back into the water; The tugboat tows the wave energy collection unit forward and away from the dock.
Fig. 12 is a schematic front perspective view of the device for extracting energy according to Fig. 8, said device now partially submerged in water by removal of some buoy panel elements (float aids) from its outer side wall surface; appears to be This is because the device has now been moved to its intended end-use location within the body of water. This unit is positioned at its location on the shoreline seabed.
13 is a schematic front perspective view of the device for extracting energy according to FIG. 8 , the device now shown partially submerged and resting on the seabed in its final position in the water, wherein the device will capture the waves and generate energy. All buoy panel elements (float aids) have been removed from the side of the device. For repeated use, both the floating dock and buoy panels are shown removed by the tugboat.
14 is a schematic front perspective view of a device for extracting energy from a vibrating fluid, such as a wave from a body of water, according to another embodiment of the present invention; The device is shown located within the surrounding body of water.
Fig. 15 is a schematic front perspective view of the device of Fig. 14; The device is shown located within a surrounding body of water; This shows a more detailed configuration of the turbine at the top of the unit.
16 is a graph showing predicted efficiency curves for a large-scale prototype unidirectional air turbine developed based on the apparatus of the present invention.
Figure 17 is a graph of the energy balance found for a vented frequency column device, a device of the type of the present invention.
18 is a time series plot of model scale air chamber pressure from experimental data (top plot); and the adjacent incident wave probe level (dashed line) and average surface height (solid line) in the lower plot.
Figure 19 shows the pneumatic power results for a test wave energy capture device obtained from regular waves (237 data points) from experimental data.
20 shows the pneumatic efficiency for a test wave energy capture device obtained from regular waves (237 data points) from experimental data.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to features of a device for extracting energy from a vibrating working fluid, for example an ocean wave repeatedly entering and exiting the device during use. The invention also relates to features of the device that maximize the capture of the surf. The invention also relates to a method of manipulating and controlling the device to maximize the amount of energy produced. The device has a design that allows greater energy production per unit flow of fluid than techniques known in the art.

Referring to the drawings, the device shown in FIGS. 1 and 2 includes a duct 10 having two arm portions 12 and 14, each arm portion comprising an elongated conduit of generally rectangular cross-section, The two arm parts are arranged at right angles to each other and are connected in a generally L-shaped structure when the duct 10 is viewed from the side (in other embodiments, for ease of reference in this description, similar parts have the same part numbers) is granted).

The first conduit 12 of the duct 10 is such that, when in use, the duct is substantially submerged below the mean water level (MSL) of a body of water 16 in which the duct is positioned to rest on sand and rock 18, for example on a marine shoreline. It is arranged and oriented with its elongated axis aligned with the sand and rock 18 in a generally horizontal orientation.

The first conduit 12 has a rectangular open mouth 20 arranged to receive a surging wave flowing in from a body of water, and the mouth 20 is a body of water that is the source of the wave, for example, the sea or Oriented outward into the lake. As shown in FIG. 1 , since the cross-sectional area is reduced when the first conduit 12 moves inward in the direction from the open mouth 20 to the interior of the duct 10 and toward the second conduit 14 , the cross-sectional area of the mouse 20 is greater than the cross-sectional area at any point in the remainder of the first conduit 12. For reasons that will become apparent when an oscillating flow is created in use, the general tapering effect of this solid walled first conduit 12 is to accelerate the flow of surging waves from the body of water 16 into the duct 10.

In the embodiment shown, a portion of the upper wall 22 of the first conduit 12 slopes downward and, in use, slopes toward a flat base floor 24 resting on sand and rock 18. A vertical side wall surface 26 extends between the flat base floor 24 and the upper wall 22 of the first conduit. In the embodiment shown, the tapered entry area of the first conduit 12 extends for about 1/3 of the length of the conduit 12, but in other embodiments it may be a different proportion. For example, the first conduit can include an inclined upper wall over its entire length, together with a flat base floor 24 and vertical sidewalls 26 extending between the base floor and the upper wall. there is. In another embodiment, the first conduit may have a top wall and a base floor that both slope inward toward each other over a portion of the length of the conduit as they move inward in a direction from the open mouth into the conduit. In another embodiment, the side walls of the first conduit may also be inclined to taper inward to form a conduit with a narrowing width such that the conduit has a reduced cross-sectional area as it moves inward in the direction from the open mouth into the duct. have

In the illustrated embodiment, the outermost and uppermost region 28 of the mouse 20 of the first conduit 12 is arranged such that, in use, it extends above the MSL of the body of water 16 in which the conduit is located, so that the mouse 20 A wave-piercing lip (30) is formed. This feature may help catch and direct a larger flow of surf from the body of water 16 into the duct 16, especially if the movement of the body of water is rough or choppy.

The second conduit 14 of the duct 10 is arranged such that in use it extends substantially above the MSL of the body of water 16 in which the conduit is located, with its elongated axis generally perpendicular to the axis of the first conduit 12. Oriented. The second conduit 14 is elongate and extends from the first conduit 12 and is arranged to receive water from the surf after the surf has flowed through the first conduit 12 . After the incoming water flows through the first conduit 12 and into the second conduit 14 of the duct 10, it flows freely out of the second conduit 14 back through the first conduit 12 and into the body of water 16 , thereby setting the frequency flow within the duct 10 which may be arranged to match the flow of incoming and outgoing waves at the shoreline of the body of water 16. The second conduit 14 extends to a height above the maximum water level 32 of the received water from the surf after the wave has flowed through the first conduit 12 . A volume of gas (typically air) located above this maximum water level 32 can be displaced out of the uppermost region of the second conduit 14 and then drawn back into that region, as will be described shortly.

To facilitate frequency flow, the internal dimensions of the duct 10 at the transition surface to which the conduits 12 and 14 are connected are identical. The first conduit 12 and the second conduit 14 also have a flow direction control segment in the form of a planar inclined portion 34 arranged at the junction of the two conduits 12, 14, which allows the rushing water to From horizontal axial flow to vertical axial flow direction within the duct 10, and then from vertical axial flow to horizontal axial flow as the water vibrates in the reverse direction and flows outward from the duct 10 toward the body of water 16. It makes it easy to be able to turn in the direction. If the cross-sectional area of the first conduit 12 becomes narrower as the fluid progresses into the duct 10, the fluid velocity will increase, which in turn drives the fluid column formed within the duct 10 to move more quickly. can vibrate

As the water is received from the surf, it is provided in the uppermost region 36 of the second conduit 14 and above the maximum water level 32 through a number of flow control devices in the form of butterfly valves or one-way check valves 38. There is a displaceable mass of air that can exit the uppermost region 36 and the flow control device can be opened automatically or arranged to be turned or moved to an open position. The uppermost region 36 inside the second conduit 14 (and above the maximum water level 32) defines a flow path 40, which is also in fluid communication with the one-way turbine 44. In the embodiment shown herein, valve 38 and turbine 44 are in direct fluid communication with flow path 40, which means that movement of air into and out of flow path 40 occurs before the air reaches the turbine. does not pass through, or vice versa. That is, the valve and turbine are not arranged in series with each other, but rather in a parallel operating configuration with each other and are located at separate spaced openings in the walls of the flow chamber 40 within the second conduit 14. . This arrangement allows for selective changes in the configuration of flow path 40, so that the working fluid (eg, air) can act unidirectionally on the turbine, or instead act in a bypass configuration (ie, bypass the turbine). ) so that it can flow unidirectionally through the discharge valve. As will be explained, at the uppermost end of flow path 40, this valve and turbine is above a range of water levels in a sea, lake or other body of water.

Referring now to FIG. 3A , the moment of initiation of the wave traveling towards the duct 10 is shown, and the wave-piercing lip 30 of the first conduit 12 and the narrowing cross-sectional area are used to direct the oncoming waves to the duct 10. ) serves as a guide. In FIG. 3B, the waves travel in the direction of arrow 42 through the duct 10, and part of the air in the flow path 40 in the uppermost region 36 is caused by water rising vertically in the duct 10. It is displaced, flows out of the butterfly valve or one-way check valve 38 and is discharged to the atmosphere. The valve 38 is arranged to have a light feathered movement, so that the flow of air in the flow path 40 is not intended to cause any significant amount of air to leave the flow path through the one-way turbine 44. , sufficient to open the valve and provide a path of least resistance out of the duct 10.

In Fig. 3c, the wave then moves through the duct 10 through the mouth 20 and towards the body of water 16 in the direction of the arrow 46, which is opposite to the direction 42 of the surf as shown in Fig. 3b. ) outward and backwards. As a result of the flow in the outward direction 46, atmospheric air is drawn into the flow passage 40 in the uppermost region 36 by the suction created by the water leaving. Since the butterfly or one-way check valve 38 is now fully closed, air can only be drawn in through the one-way turbine 44 and this flow of air rotates the turbine 44 to produce electrical energy.

In some other embodiments, when atmospheric air is drawn into the flow passage 40 in the uppermost region 36 by the suction produced by the leaving air, the valve is not completely closed against this air flow, but rather the air passing through it. It may be of a flow restricting type or may be arranged in a position of partial closure. However, most of the air being sucked into the flow path 40 passes through the one-way turbine 44 . Thus, all airflow into and out of the flow passage 40 responds to and is produced by the vibration of the frequency column within the duct 10, which is set by the repetitive wave flow frequency at a particular location.

In another device disclosed herein, the flow situation shown in FIGS. 3b and 3c can be reversed so that as the waves travel into the duct 10, the flow path 40 in the uppermost region 38 is released to the atmosphere. The air in ) is displaced by the rising water in the duct 10 and flows out of the one-way turbine 44 . In this device, when a wave travels from the duct 10 through the mouth 20 and towards the body of water 16, the atmospheric air is then drawn back into the flow path 40 through the valve 38, which is a one-way valve. It is arranged to open more easily in one direction into the flow passage 40 than can flow through the turbine 44 and into the flow passage 40 . However, the inventor's research has revealed that the efficiency of such an arrangement is significantly lower than that achievable by the flow situation shown in Figs. 3b and 3c. It is during the downward stroke of the air intake into the flow path 40 (i.e., the fall or suction of the waves from the frequency chamber) that provides the maximum power generation characteristics, and the energy produced by the rotation of the turbine 44 in this configuration is Significantly greater than can be achieved (i) using a bi-directional turbine, or (ii) using the pressure of an upward stroke of air pressure into the duct and towards the turbine, such as from surging waves (the latter being energy weakest).

Referring to the embodiment shown in FIGS. 4 and 5 , a slightly different appearance of the duct 10 is shown. In all respects, it is functionally similar to the previously described embodiment. Each arm portion 12, 14 includes an elongated conduit of generally rectangular cross-section, which is arranged at right angles to each other and connected in a generally L-shaped configuration.

The first conduit 12 of the duct 10 is arranged to be substantially submerged below the Mean Water Level (MSL) in use, and is oriented generally horizontally with its elongated axis aligned with the sand and rock 18. Oriented in state. In the uppermost region 36 of the second conduit 14 there are a number of flow control devices in the form of butterfly valves or one-way check valves 38 which can be opened automatically or arranged to be turned or moved to an open position. It can be. The uppermost region 36 inside the second conduit 14 (and above the maximum water level 32) defines a flow path 40, which is also in fluid communication with the one-way turbine 44.

Geometric design features employed by the present inventor include the introduction of a sloping front lip and pointed bow 33, shown in FIG. 5, to reduce wave loads on the front face of the duct 10.

Referring to the embodiment shown in FIGS. 14 and 15 , a slightly different appearance of the duct 10 is shown. In all respects, it is functionally similar to the previously described embodiment. Similar part numbers are used to describe functions.

In another embodiment, valve 38 is equipped with a control mechanism to control its opening and closing configuration. For example, the valve may have a gate that is opened and closed against the flow of gas by a hinged motion, or by a sliding motion, or by a rotatable motion to cover at least a portion of the cross-sectional open passage of the valve. In another embodiment, the valve used may be configured in any other suitable direction to respond to changes in the direction of flow and/or pressure of the oscillating air entering and exiting the flow path 40 .

Importantly, access to the displaceable gas in flow path 40 in uppermost region 36 of second conduit 14 is not only through one-way turbine 44 but also through one or more valves 38 (or other forms of flow). control device), it is possible for the system to be configured to operate each type of access to the flow chamber separately and sequentially relative to the others. In doing so, this means that the design of the turbines 44 can be significantly simpler than prior art in-pole arrangements for power generation, many of which utilize a turbine rotating unidirectionally on a shaft to allow bi-directional air flow. The focus is on the development of new turbine designs that can cope with In this conventional installation, the gas in the passage in the uppermost region of the second conduit is displaced by the vertically rising water in the duct and flows out of the one-way turbine and is discharged to the atmosphere, but when the gas is drawn back into the passage by suction, It needs to flow through the same unidirectional turbine but in the opposite direction, which requires a very complex adjustable flow turbine design.

In this system, the turbine 44 is of a basic known design and includes a rotor 48 comprising a central hub 50 located on one end of a rotatable shaft and arranged around the periphery of the hub 50 and from the periphery. A rotor 48 containing a plurality of elongated blades 52 is disposed within a housing 54 in fluid communication with a flow path 40 . The shape of the turbine blades 52 and their orientation relative to the hub 50 facilitate unidirectional rotation of the turbine rotor 48 in response to a unidirectional axial flow of gas through the turbine housing 54 .

As is typical for this type of turbine, a generator is configured for rotation by the turbine to produce electrical energy, at one end of the drive shaft of turbine 44 at the other end of the drive shaft relative to the position of hub 50. It is connected.

The described system has another significant operating advantage over the known prior art due to its ability to adjust the direction of valve 38 to respond to changes in the direction of flow and/or pressure of the oscillating air. For example, by opening or closing a number of valves 38 located in the second conduit 14 in the portion extending above the MSL, the frequency of the oscillatory columns in the duct 10 may be “tune” to allow for the push from the sea. It is possible to tailor the frequency of the movement of incoming and outgoing waves. By doing so, the air pressure resistance in the flow path 40 of the uppermost region 36 of the second conduit 14 opposing the rising water in the duct 10 can be regulated. When the frequency of the oscillatory waves flowing into and out of the duct 10 substantially corresponds to the frequency of the incoming and outgoing waves from the body of water 16, the oscillatory streams within the duct 10 continue with the waves. The operation of the energy extraction device will then be smoother and more efficient, rather than having to operate in a situation where the sequence is reversed and thus subject to excessive turbulence and inefficient drawing of air into the turbine 44 .

This "tuning" of the frequency of the oscillatory flow within the duct can be accomplished by automating the adjustment of valve openings, for example using a control mechanism that responds to measured changes in the pressure of incoming and outgoing waves to excellent wave conditions. can be performed continuously. In such a device, the control mechanism may selectively open or close (or partially open or close) one or more valves 38 . This adjustment reduces the available cross-sectional area of the openings to and from the flow path 40 in the uppermost region 36 of the second conduit 14 of the duct 10 to the entirety of the second conduit 14 overlying the MSL. surface area ratio, and this ratio is now defined by the present inventors as the "optimal venting ratio". In one example, the optimal venting ratio is less than 15%, but optimal venting ratios of less than 10% may also be suitable. Depending on the average wave height of the waves and the period of the waves (sea conditions can be very calm or very rough), a lower or higher optimum, for example, to optimize the time the frequency flow spends in the duct 10, is selected. Venting ratios as low as 1% may be required

In another example of "tuning" the frequency of the oscillatory flow within the duct, when storm surge conditions are hazardous or violent, such as during a storm, a valve opening control mechanism may be used to build a pneumatic head within the flow path 40 such that sufficient The water valve 38 can be closed and locked. This “de-tuning” can serve as a safety feature by precluding the strongest waves from the sea from reaching far into the duct and thereby possibly protecting valves and turbines from storm damage. there is.

As shown in FIG. 2 , the uppermost region 36 of the second conduit 14 of the duct has four butterfly valves 38 present on the rear, upper, vertical side wall surface 56 of the duct 10. and three butterfly valves 38 presenting on the uppermost horizontal wall 58 of the uppermost region 36 of the second conduit 14. In other embodiments, more or less than this number of valves 38 may be installed at the time of initial construction of the duct, depending on the location and expected wave strength to be encountered, whereby it is designed to change the maximum possible venting ratio of a particular duct. characteristic. In other embodiments, the types of valves may also vary, and combinations of different types of valves (butterflies, one-way check valves, etc.) may also be mounted in one duct.

As the waves enter the duct 10, they open the valve(s) 38 followed by closing the valve(s) 38 and as the waves leave the duct 10, air passes through the turbine 44. When the repeating phases drawn into the second conduit 14 reach a stable pattern, the turbine 44 and generator are transferred from the duct 10 (if located offshore) to land (on the coast) by insulated high voltage copper cables. It will generate electrical energy that can be

As a general, non-limiting indication of size, a typical duct has a first conduit approximately 8 to 10 meters long and a second conduit extending 15 to 18 meters above the reference surface or ocean shoreline of the body of water in which the duct is located. The duct structure is typically made of reinforced concrete in order to have the weight and strength to withstand the repeated pressure exerted by waves in a corrosive salt environment.

The inventors have found from experimental results using the new energy extraction device that there is a significant increase in energy capture from a unidirectional turbine 44 configured to operate with a unidirectional flow of air rather than a unidirectional turbine configured to operate with a bidirectional flow of air. During an equivalent operating period, as air is drawn through turbine 44 and into flow path 40 as waves travel in duct 10 toward body of water 16, the energy produced is known to have flow operating in the same direction. 16% better than could have been achieved using a bidirectional turbine design. It is believed that this improved result is caused by a combination of the downward hydrostatic pressure head of the frequency column located in the second conduit 14, in addition to the suction withdrawal of the body of water 16 as it draws water from the duct 10. Thus, since the system can be configured to separate the release and intake stages of air with respect to the flow path 40 using different devices, it is possible to capture energy only from the gas flow operating in response to the wave outflow from the duct. is possible, which is also the flow with the highest potential energy.

The inventors have also found from experimental results using the new energy extraction device that there is a significant increase in energy capture when the feature of the wave piercing lip 30 is added to the open mouth 20 of the first conduit 12. The accelerated transfer of the surf flow into the duct 10 results in a further improvement of 20% in the energy that can be produced when compared to known vibrating duct arrangements without this feature. This feature moves more fluid into the duct 10 which in turn causes more air to be drawn through the turbine 44 and into the flow path 40 of the second conduit 14 as the waves leave the duct 10. It is believed to make The wave piercing lip 30 of the present invention is arranged so that it is almost always visible over the MS of a wave at a specific location.

It is difficult to safely position heavy and rigid devices such as vibrating fluid ducts in water at the edge of a body of water. Accordingly, the present inventors have devised a method of positioning the device using a submersible floating dock 35 (such as a dry dock). Reference should be made to the sequence of FIGS. 8 to 13 .

While not submerged, dock 35 can be moved by towing behind shipping vessel 37 for underwater positioning of device 10 . The vibrating wave column device 10 is itself equipped with a flotation aid 41 for use when required for positioning in the final stage. When the assembled vibrating fluid duct is ready for installation, it is placed on a submersible floating dock (or built on top of its platform during the construction phase). Unsubmerged floating docks and ducts are towed behind shipping vessels, e.g. tugboats, using long cables (39) for intended destination of devices on water bodies, such as ocean edge/surf edge areas. can be moved in the direction of

Once near its final position, the floating dock can be submerged, and the duct is kept afloat by its own flotation aids. This floating aid can be of many forms, such as hollow buoy panels, inflatable gas balloons, and the like. When the floating duct and the submerged floating dock are separated from each other, the floating duct itself can be towed a short distance to its desired final operating position, and the floating aid is then removed or retracted. This unit will then settle in its position on the seabed offshore under gravity and remain partially submerged in its final position in the water, where it will catch waves and generate energy.

Using submersible docks offers great advantages such as handling stability for these large devices as they move across the open sea to reach remote shorelines for final installation. A floating dock minimizes the risk of the ductwork capsizing or sinking in bad weather.

experimental part

Experimental performance results are presented for this embodiment of a frequency column (OWC) as a wave energy converter (WEC). The operating principle for this unit is to open during positive pressure times thereby venting the air chamber and to close when the air chamber pressure is negative, thus drawing air through a unidirectional air turbine power take-off (PTO). uses an air valve. Results are presented for both regular and irregular seas.

The prototype top lip and front wall geometry are design features that appear to positively influence the operating characteristics of the device. Experimental results indicate that this unidirectional prototype will exhibit very good energy harvesting capabilities over a wide range of wave frequencies.

The OWC is a large hollow concrete chamber that is partially submerged, sits on the seabed and is vented to the sea through an underwater opening. The chamber in which the air turbine is housed also contains a small opening to the atmosphere above the waterline.

As the rupture and parangol pass through the normal OWC, water enters and exits the chamber through the chamber's waterlogged opening. This water rises and falls inside the chamber, causing the pressure of the air trapped above to oscillate between positive and negative pressure. In some earlier embodiments, these pressure fluctuations force air through the bi-directional turbine at the top of the chamber, in order to thereby reliably generate electricity.

The basic conceptual difference between the OWC of the present invention and the conventional OWE is that the turbine is exposed to airflow from only one direction. A manual air flow valve allows air to exit the chamber but not return. This results in simpler design constraints which means it can be optimized for unidirectional air flow. Also, the turbine exhibits low frictional losses.

Although air is transferred through the air turbine for only half of the wave cycle, almost all of the energy from the full wave cycle (minus normal turbulence and frictional losses) is available for extraction. This process is explained in more detail by energy balance, as shown in FIG. 17 .

A. One-way air turbine power take-off

)에 대한 예상 터빈 효율이, Aoleus 평균선 터빈 성능 분석으로 생성된 도 16에 나타나 있다. (각속도가 곱해지고, 체적 유량이 곱해진 압력 강하로 나누어진 토크의 곱으로서 측정된) -30kPa에 이르는 일반적인 작동 범위에서 가중 평균 터빈 효율은 650 RPM의 일정한 터빈 회전 속도에 기초하여 77%이다.The inventors have developed a conventional stator+rotor type turbine design to extract power from the airflow induced by the air pressure of the OWC. First, the turbine operates with a one-way air intake over a very wide range of pressure drop conditions. Turbine air differential pressure (

The expected turbine efficiency for ) is shown in FIG. 16 generated by Aoleus Mean Line Turbine Performance Analysis. The weighted average turbine efficiency over a typical operating range up to -30 kPa (measured as the product of torque multiplied by angular velocity and divided by pressure drop multiplied by volume flow rate) is 77% based on a constant turbine rotational speed of 650 RPM.

B. WSE OWC Geometry

Geometric design features employed by the present inventors include the introduction of a sloping front lip and pointed bow, most evident in FIG. 5 . This geometrical enhancement was included with the goal of improving hydrodynamic performance and reducing wave loads on the front of the OWC.

C. King Island Prototype

King Island is located in the western waters of Bass Strait, approximately equidistant between Tasmania and mainland Australia. The island, with a population of about 1,700, is powered by its own grid system consisting of wind turbines, some solar and storage batteries, supplemented by diesel power generation.

King Island's pilot plant project is located approximately 700 m from the coast, at an average sea level depth of 10 m. The new design of the OWC unit for this project will be 20 meters wide and will have a nominal maximum electricity generating capacity of 1 MW. Wave conditions for this location are greater than 45 kW/m, which ranks among the best in the world in terms of wave energy sources. A bathymetry and sub-bottom profiling of the proposed site, located close to suitable grid connections, was completed.

Experiment setup

Experiments were performed in the Australian Maritime University's model test basin (MTB), which is 35 m long, 12 m wide and 1 m deep, but can be filled to a depth of 333 mm, equivalent to 10 m deep in a full-scale prototype. The MTB is equipped with a 16-piston type drill paddle at one end and a passive beach at the other end. The model was positioned at the center of the MTB 12 m from the driller.

A 1:30 scale model was made from plywood with a clear acrylic side to allow visual observation of the inner chamber water level. 3D printed manual check valve bodies are mounted on the back and sides of the model, with an acetate seat lightly hinged to the top edge of the body to allow the valve to open with minimal chamber air pressure. First, a power take-off (PTO) was simulated using an orifice plate that exhibited a non-linear pressure/flow relationship similar to that of a turbine.

Air chamber differential pressure was monitored using three separate pressure transducers (1 psi Honeywell TSC sensor calibrated by an Ocean Controls instrument amplifier KTA 284), one on each side of the chamber roof and one on the side of the top transparent box. It was found that each pressure sensor produced approximately the same value (see eg FIG. 18 ). Chamber surface elevation was monitored by means of six resistive wave probes. The wave probe was connected to the data acquisition system through the HR Wallingford wave probe signal conditioning box.

Data was acquired at 200 Hz using a 16-bit National Instruments PCI card (NI PCI-6254) connected to a BNC terminal box. Data recording was triggered using wave paddle motion, and recorded for 30 seconds for regular waves and 600 seconds (equivalent to 30 minutes in life size) for irregular waves.

methodology

A. Sea conditions

Both regular and irregular waves were investigated in this analysis. Life-size equivalent irregular waves (JONSWAP) are summarized in Table 1. The irregular wave conditions tested were selected based on conditions expected to occur at the King Island test site. Regular waves were selected to be tested to include wave heights and frequencies of irregular waves. Wave calibration tests were performed without the WEC model in a water bath.

Life-size irregular waves tested on MTB Irregular waves Hs and Tp 0.6m 6.5s
0.6m 8.8s
0.6m 10.7s
0.6m 12.4s
0.6 m 15.0 s
0.6m 17.1s
0.6 m 18.9 s
1.4 m 9.0 s
1.4m 10.8s
1.4 m 12.4 s
1.4 m 14.9 s 1.4 m 19.1 s
1.4 m 17.2 s
1.5m 6.5s
1.5 m 9.0 s
1.8m 10.8s
1.8 m 14.9 s
1.8 m 19.0 s
2.1 m 12.6 s
2.2 m 9.2 s
2.2m 10.8s
2.2m 14.8s 2.2 m 17.2 s
2.2 m 19.0 s
2.4m 6.5s
2.6m 10.8s
2.7 m 19.0 s
2.7m 14.8s
3.0m 6.5s
3.0m 9.2s
3.0 m 12.6 s
3.0m 17.3s
3.1 m 10.8 s 3.1 m 14.8 s
3.1 m 19.0 s
3.3m 6.5s
3.4 m 9.2 s
3.4m 12.6s
3.4m 17.5s
3.5m 10.3s
3.6m 12.7s
3.6m 17.5s
3.8m 10.3s
4.1 m 12.6 s

B. Pneumatic power Pneumatic power is calculated as follows.

는 공기 챔버 차압이며,

는 공기 체적 유량이다.here,

is the air chamber differential pressure,

is the air volume flow rate.

Due to the selected model ratio (1:30), air compressibility is considered negligible. The air inlet rate is calculated from the air chamber differential pressure using the equation:

는 오리피스 배출 계수이며,

m²는 제한 오리피스 횡단면적이고,

=1.4kgm^-3는 공기 밀도이다. 인-시튜 교정(in-situ calibration)은 공기 유입에 대해 계수를

가 되도록 결정하였으며, 이는

가 흐름 평가를 위하여 합리적이고 보수적인 것을 의미한다. 챔버에는 공기 밸브가 장착되어 있기 때문에; 공기 유출은 동력 생산에 기여하지 않으며, 또한 A_O가 변수가 되기 때문에 공기 압력차를 이용하여 공기 유출을 신뢰성있게 예측할 수 없다.here,

is the orifice discharge coefficient,

m ² is the limiting orifice cross-section;

=1.4 kgm ^-3 is the air density. In-situ calibration measures the air entrainment.

It was decided to be, which

means that is reasonable and conservative for flow assessment. Because the chamber is equipped with an air valve; Air leakage does not contribute to power production, and since A _O is a variable, air leakage cannot be predicted reliably using the air pressure difference.

C. incident wave force

The regular wave force is calculated by linear theory using mid-depth calculations according to the equation below.

1000kgm^-3는 물 밀도,

ms^-2는 중력 가속도, h는 마루에서 골까지 측정된 파고이다. 평균 불규칙 파력은 하기와 같다.where E is the energy density (energy per unit surface area), C _g is the wave group celerity resolved for intermediate depths,

1000 kgm ^-3 is the density of water,

ms ^-2 is the gravitational acceleration, h is the wave height measured from the crest to the trough. The average irregular wave force is as follows.

이고,

는 (파도 기록의 한 표준 편차와 동일한) 제1 분광 모멘트이며,

는 (분광 분석에서 유도된) 에너지 주기(

)이다.here,

ego,

is the first spectral moment (equal to one standard deviation of the wave history),

is the energy cycle (derived from spectroscopic analysis)

)am.

D. Pneumatic efficiency

Pneumatic efficiency is defined as the ratio of the extracted pneumatic power divided by the equivalent wave power across the width of the device.

where W is the device width facing the wave front.

E. Scaling of Results

)에 따라 실물 크기로 스케일하였으며, 물 밀도의 차이는 무시된다.Results are shown in Table 2 (using simplified Froude-like scaling)

), and the difference in water density is ignored.

Proud Scaling unit jisoo length λ enter λ power λ ^7/2 hour λ ^1/2

F. Energy Balance Energy balance is a visual representation of energy flow from a source to temporary storage and finally to a sink. Figure 17 shows the energy balance for OWC with an additional path for the air valve. Solid lines and arrows show possible directions of energy flow within the system. Dashed lines show less significant energy flow connections. For 100% pneumatic conversion efficiency, all the energy must flow from the surging wave (source) to the power take-off (sink). Practically speaking, not all energy within a wave wave can be extracted, where some energy ends up being useless. form (viscous loss, such as boundary effect, or turbulent loss, such as vortex emission) or reverberated at the WEC or diffracted around the WEC. The basic path of energy flow for any type of OWC WEC is from the surf to the water column heave and then to the power take-off (air turbine) driven by the air pressure difference between the air chamber and the atmosphere. For OWCs with bi-directional air turbines, there is no air valve, so the pressure differential drives the turbine during the entire cycle.

)과 공기 유량(

)의 곱이다. 이 사이클의 이 절반 동안 공기 밸브 (터빈 기하학적 구조에 따라 잠재적으로 PTO)를 통한 에너지 손실은 이 기간 중의 공압 동력의 적분값이다.For the concept where the air valve is present, during the first half of the conversion cycle the water level rises causing the air chamber static pressure. Air then flows through the air valve, and energy is also stored in the form of potential energy as water column heave. As defined by Equation 1, the pneumatic power is the air differential pressure (

) and air flow rate (

) is the product of The energy loss through the air valve (potentially the PTO depending on the turbine geometry) during this half of the cycle is the integral of the pneumatic power during this period.

Since minimizing conversion losses is the main objective, the power consumed by the valve must be minimized. Since the air flow must be unobstructed to enable maximum energy storage as a water column heave, after physical considerations in Equation 1 this can be achieved only by minimizing the pressure differential. In practice, this is achieved by maximizing the air valve area and using a valve with a low back pressure.

During the second half of the cycle, the water level begins to drop causing air chamber negative pressure. The air valve is closed so that all incoming wave energy up to the energy stored in the water column heave is available to the PTO, which in the case of the WSE concept is a custom one-way air turbine.

18 is a plot of experimental data showing the relationship between air chamber pressure, chamber water column heave (reservoir) and passing water profile adjacent to the water column (incident wave). It is clear that the air chamber pressure is only slightly positive while the chamber level is rising (minimum energy loss through the air valve) and significantly negative while the chamber level is falling.

result

The results are presented in the following section for unit power performance in head seas when exposed to both regular and irregular waves. Both full-scale extrapolation results and efficiency results are presented.

rule wave result

, 여기서

는 원하는 높이이며,

는 실제 물마루에서 골까지의 높이)을 적용하였다. 더 큰 파고 (2.7m 및 3.0m)의 경우, 동력 출력은 다소 불규칙하게 보이며, 이는 챔버 내에서의 수위가 챔버와 전방 립을 지난 대기 간의 별도의 대기 연결을 위하여 충분히 떨어짐에 따라 챔버로부터의 압력 손실의 영향을 받는 것으로 밝혀졌다.Figure 19 shows the regular wave pneumatic power results extrapolated to full scale. Results were compiled from 237 separate runs of the driller. Due to the deviation of the generated wave height from the desired one, a linear correction to the pneumatic power (

, here

is the desired height,

is the height from the actual trough to the trough) was applied. For larger wave heights (2.7 m and 3.0 m), the power output appears somewhat erratic, as the water level in the chamber drops sufficiently for a separate atmospheric connection between the chamber and the atmosphere past the front lip, thereby reducing the pressure from the chamber. found to be affected by losses.

During the changing wave period, it can be seen that there is an almost equal production of pneumatic power between periods of 8 and 12 seconds, followed by a drop from 13 to 16 seconds and a moderate increase and uniformity from 16 to 18 seconds. there is.

20 shows the pneumatic efficiency of the device acting on regular waves. Peak efficiency was shown to occur in just under 8 seconds with values of about 1 to 1.1 (improving for lower wave heights). There is a second lowest peak at 12 seconds with a pneumatic efficiency of about 0.8 to 0.9, and this second peak was estimated to be related to the anterior lip and pointed bow geometry. For wave periods longer than 12 s, the efficiency decreases rapidly after 14 s until it levels out between 0.3 and 0.5.

Efficiency losses for longer period waves were considered somewhat less detrimental because longer period waves also generally contain more energy than shorter period waves. However, referring again to FIG. 19, there was still a significant decrease in pneumatic performance during the wave period between 13 and 15 seconds, which is reserved for further study.

irregular wave result

) 사이에서 일어났다. 마찬가지로, 효율은 13초가 포함된 13초까지 모든

에 대하여 0.5를 훨씬 넘는다.The predicted full-scale pneumatic power matrix results were calculated from a total of 47 different wave records using the griddata function, and 2D linear interpolation was performed. Similar to what was revealed in the rule wave results; Pneumatic power production was best for the lower periodic waves, with the best average power production peaking at 11 to 13 seconds (

) occurred between Similarly, the efficiency is all up to 13 seconds including 13 seconds.

far exceeds 0.5 for

Argument

Air compressibility is known to yield lower pneumatic performance for real seas compared to Froude scale extrapolated model test results. Other researchers have investigated this issue using 3D numerical codes and have found an overestimation of about 12% for a typical OWC PTO. Therefore, this simple calibration can be applied to performance evaluation by reducing pneumatic power extrapolation results. However, it is also known that the efficiency decrease is a function of the air compressible volume. Since the OWC of the new concept of the present invention raises the chamber water surface altitude higher, the chamber air volume is consequently reduced. However, it is possible that the 12% estimate of the scaling error is rather extreme, as this concept involves only rarefaction and not compressibility. Also, a conservative flow coefficient of 0.6 (instead of the bounded 0.691) is considered a sufficiently conservative estimate to compensate for any scaling problems in this case.

The improved pneumatic power production of this new technology (as described in the previous section) combined with turbine efficiency (average 77.5%) and assumed electrical conversion efficiency of 95% results in a significant power increase compared to previous bi-directional OWCs. When considered with measured wave conditions at the King Island site, the pilot plant project is expected to exhibit an average power output of 472 kW (implying a capacity factor of 47.2% for a 1 MW peak unit). Given an operational assumption of 8,500 hours per year, this would result in an annual energy production of over 4 GWh.

The wave to wire efficiency of a system is often described as “power out divided by power in”. The average “output power” of the proposed King Island pilot plant units has already been estimated at 472 kW (see above). "Input power" is defined as the average incident wave energy density (kW per meter of wave crest) multiplied by the width of the device in meters. A detailed assessment of wave conditions at the King Island site revealed an average incident wave energy density of 52.87 kW/m. Multiplying the unit width of 20 meters gives an average wave power coming into the WSE unit ("power in") of 1057 kW. Therefore, the wave-to-wire efficiency of the WSE device is estimated to be 44.6%.

This level of energy production, combined with the project's projected full life cycle cost, represents a Standard Energy Cost (LCOE) for this one-time commercial project of US$0.13 per kWh. Direct economies of scale for multi-unit projects over 25 MW using the same technology represent an LCOE of less than US$0.07 per kWh.

conclusion

Details of OWC technology, including new innovations, are presented. This technology addresses OWC's air rectification problem for use with efficient unidirectional air turbines. The rectification system combined with tailored geometric transformations was tested at model scale in both regular and irregular waves. Performance results in irregular seas yielded a maximum pneumatic efficiency of 83%. In regular waves, the highest pneumatic conversion efficiencies were found to exceed 100%. This was due to the device's resonance with the surging waves causing deformation of the local wave field. This phenomenon causes the device to extract more energy than is naturally incident on the face of the OWC.

The net result of this improvement in the conversion efficiency of the new concept OWC device is a corresponding reduction in energy generation costs. For a multi-unit wave energy project at a location with wave conditions similar to those of King Island, rigorous financial analysis suggests an LCOE of approximately US$0.07. This is exceptional as an energy technology in the early stage of commercialization. Learning curve studies show that this LCOE will fall further over the next decade.

The device disclosed herein has many advantages over previous OWC technologies as well as conventional power generation devices:

- the device can be operated in resonance with the incident wave field (fitting the turbine damping characteristics to the OWC);

- column/duct dimensions can be designed with optimal hydrodynamic conversion efficiency of the OWC structure (site-specific OWC design for possible incident wave fields);

- Turbine performance/efficiency for expected pressure/flow characteristics can also be optimized;

- The unit can be mechanically disconnected in storm conditions to prevent damage by shutting off the valve. Because of its robust construction, the device will not be blown away in a storm;

- Experimental performance of the OWC device showed very good energy harvesting capability over a wide range of wave frequencies and provided a significant improvement in power compared to previous bi-directional OWCs;

- Simpler and more efficient one-way air turbines, safely positioned well above the action of the waves and protected from storms by concrete caissons, capable of withstanding extreme conditions. An exemplary device would be 20 meters by 20 meters in size and 18 meters in height. Of these, only 8 meters protrude above the waterline. The generating units will generally be located some distance from the shore in a depth of 10 meters.

- It is envisaged that a farm (or array) of offshore wave energy converters may be used. Using this unit as a coastal breakwater (or breakwater) provides a powered and protected harbor for both community and industry while also realizing significant cost-sharing and savings potential.

- The moving parts within the overall technology are just a turbine and some simple off-the-shelf valves, all well above the waterline. There are no moving parts in or under water. This means that maintenance only needs to be carried out in accessible areas far above the sea. The operation of many other wave energy devices takes place underwater, which leaves the device exposed to the corrosive and damaging effects of salt water and makes the device difficult to maintain or repair. The turbine and generator are kept above the waterline, meaning they are low-maintenance and any maintenance can be done without the need for scuba equipment.

- As there are no moving parts underwater, the device prevents injury to marine life. No oil or contaminants can spill.

- The reliability and predictability of waves is a huge advantage over solar and wind power. For example, many weather and surfing websites accurately predict wave conditions a week in advance - so this renewable source can be considered a supplemental baseload power source.

In the foregoing description of specific embodiments, specific terminology has been used for purposes of clarity. However, the present invention is not intended to be limited to the specific terms so selected, and each specific term should be understood to include other technical equivalents operating in a similar manner to achieve a similar technical purpose. Terms such as “upper” and “lower”, “above” and “below” are used as words of convenience to provide a point of reference and should not be construed as limiting terms.

In this specification, the word "consisting of" is to be understood in its "open" sense, ie in the sense of "comprising", and therefore in its "closed" sense, ie in the sense of "consisting only of". should not be limited Corresponding meanings are attributed to the corresponding words "comprises", "includes" and "includes" when they appear.

The foregoing description is presented in relation to several embodiments that may share common characteristics and features. It should be understood that one or more features of any one embodiment may be combinable with one or more features of any other embodiment. Also, any single feature or combination of features of any embodiment may constitute an additional embodiment.

In addition, the foregoing description merely describes some embodiments of the present invention, and changes, modifications, additions and/or variations may be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and limiting. It is not. For example, while the particular L-shaped duct 10 shown in the drawings may be different, the two conduits 12 and 14 are not necessarily orthogonal to each other. The valves 38 may differ in their size, shape and total number. There may be one or more turbines 44 on any particular duct 10, which may be received and connected to the uppermost region 36 of the second conduit 14 by other means (eg, via a pipe). can The material of construction of the duct 10 is typically made of concrete, but may be other materials such as hard plastic or carbon fiber, and may be anchored to the rock 18 at the shore. Although reference is made to wave generation from seas or oceans, wave generation can also occur from lakes, rivers and tidal pools, all of which are suitable for use with the method and apparatus.

Further, while the present invention has been described in relation to what is presently considered to be the most practical and preferred embodiment, the present invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the present invention. It should be understood that this is intended. Further, various embodiments described above may be implemented in conjunction with other embodiments, for example, aspects of one embodiment may be combined with aspects of another embodiment to implement another embodiment. Additionally, each independent feature or component of any given assembly may constitute an additional embodiment.

Claims (44)

A device for extracting energy from a vibrating working fluid, comprising a flow path for the working fluid and a turbine in direct fluid communication with the flow path, respectively, and a flow control device, wherein, in use, the flow control device opens the flow control device. and allowing the flow of the working fluid to exit the flow path through the flow control device; device that is selectively movable between a second configuration entering the flow path through the According to claim 1,
wherein the flow control device changes the configuration of access to the flow path in response to changes in pressure and/or flow direction of the vibrating working fluid. According to claim 1 or 2,
wherein the flow control device is completely closable to facilitate flow of working fluid only through the turbine in the second configuration. According to any one of claims 1 to 3,
wherein the flow control device is equipped with a control mechanism to control its movement between the first configuration and the second configuration. According to claim 4,
wherein the flow control device has an element movable by the control mechanism to open and close with respect to the flow of the working fluid. According to claim 5,
wherein the element is either hingedly, slidably or rotatably movable and shaped to cover the cross-sectional open passage of the flow control device. According to any one of claims 1 to 6,
wherein the flow control device is either a butterfly valve or a check valve. According to any one of claims 1 to 7,
The turbine includes a rotor including a central hub and a plurality of blades arranged around and extending from the periphery of the hub, the rotor being disposed in a housing connected to the flow path, whereby the shape of the blades and the and its orientation relative to the hub facilitates unidirectional rotation of the turbine rotor in response to a unidirectional axial flow of working fluid through the housing. According to claim 8,
wherein a generator is configured for rotation by the turbine to produce electrical energy. According to claim 9,
A drive shaft is connected at its proximal end to the hub and at its distal end to the generator. According to any one of claims 1 to 10,
wherein the working fluid is air, and a flow of air is created by vibration of a frequency column located in the duct and in fluid communication with the flow path. According to claim 11,
The duct is
A. a first portion, in use, arranged so as to be submerged substantially below the Mean Water Level (MSL) of the body of water in which the duct is located, and having an opening arranged to receive surging waves from the body of water; and
B. a second portion suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from surf after a wave has flowed through the first portion;
wherein the flow path is defined by an area of a second portion extending above a maximum level of water received from the surf after a wave has flowed through the first portion. According to claim 12,
The first and second parts of the duct are connected through a flow direction control segment intermediate the first and second parts, the flow direction control segment being arranged at the junction of the first and second parts and the first and second parts. Device defined by a planar inclined portion extending between the first and second portions. According to claim 12 or 13,
wherein the first and second portions of the duct are generally elongate conduits, the first portion having a cross-sectional area greater than the cross-sectional area of the second portion. According to claim 14,
A cross-sectional area at the opening of the first portion is a larger cross-sectional area than the rest of the first portion, so as to accelerate the flow of the surf from the watershed to the conduit, the conduit may be formed outside the opening at the opening. wherein the cross-sectional area decreases when moving in a direction from the entry mouse area toward the second portion. According to claim 15,
wherein the external entry mouse area of the first part is arranged to, in use, extend above the MSL of the body of water in which the duct is located, so as to capture a larger flow of surging waves from the body of water into the duct. According to any one of claims 12 to 16,
wherein the duct is operable to lie on the seabed of a body of water in which the duct is disposed. As a blue energy extraction system,
a. As for accommodating the vibrational order,
i. a first portion, in use, arranged so as to be submerged substantially below the Mean Water Level (MSL) of a body of water in which the duct is located, and having an opening arranged to receive surging waves from said body of water; and
ii. a second portion suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from a surf after a wave has flowed through the first portion;
Thus, in use, at least one duct, in which a frequency column is built up inside as a result of the repeated movement of water in and out, and the flow of water out is also made through the opening, but in a direction opposite to the direction of the surf;
b. a rotatable air turbine in direct fluid communication with a flow path located within said second portion of said duct; and
c. at least one flow control device also in direct fluid communication with the flow path;
The flow control device, when in use, has a first configuration that permits a flow of displacement air to exit the flow path when the device is opened and the frequency column is received into the second portion of the duct, and the device is directed to the second portion. arranged to move between a second configuration restricting air flow, so that as the frequency column flows out of the duct in the opposite direction, a flow of air is drawn back into the flow path through the rotatable air turbine. . According to claim 18,
wherein the flow control device changes the configuration of access to the second portion in response to changes in pressure and/or flow direction of the vibrating working fluid. The method of claim 18 or 19,
and a generator configured for rotation by the turbine to generate electrical energy. According to claim 20,
The turbine includes a rotor comprising a central hub and a plurality of blades arranged around and extending from the periphery of the hub, the rotor being disposed in a flow path connected to the second portion, whereby the shape and shape of the blades and and its orientation relative to the hub facilitates one-way rotation of the turbine rotor in response to axial airflow through the flow path to the second portion. According to claim 21,
A drive shaft is connected at its proximal end to the hub and at its distal end to the generator. The method of any one of claims 18 to 22,
In use, the frequency of the frequency column is determined by selective movement of one or more of the flow control device(s) between the first and second configurations, as a percentage of the surface area of the second portion extending over the MSL. A system that can be varied by changing the cross-sectional area of (s). According to claim 23,
wherein the cross-sectional area of the flow control device(s) as a percentage of the surface area of the second portion extending above the MSL is determined to be less than 15%. According to claim 24,
wherein the ratio is set to be less than 10%. The method of any one of claims 18 to 24,
18. A system comprising a device as defined in any one of claims 1-17. A method of controlling the frequency of movement of water within a water column to substantially correspond to the frequency of incoming and outgoing waves from a body of water in fluid communication with the water column, comprising:
a. Arranging a duct to accommodate the frequency column, wherein the duct,
i. a first portion, in use, arranged to be submerged substantially below the mean water level (MSL) of a body of water in which it is located, and having an opening arranged to receive surging waves from said body of water; and
ii. a second portion suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from a surf after a wave has flowed through the first portion;
In use, the frequency column is built up in the duct as a result of the repeated movement of water into and out of the duct, and the flow of the water out is also through the opening, but in a direction opposite to that of the surf;
b. changing the configuration of at least one flow control device in direct fluid communication with the flow path inside the second portion of the duct extending above the MSL;
The device(s), in use, has a first configuration allowing a flow of displacement air to exit the flow path when the device is open and the frequency column is being received into the duct, and the device passes through the device to the second configuration. arranged to move between a second configuration restricting air flow to said flow path within the section;
Thus, the frequency of the oscillatory waves flowing into and out of the duct substantially corresponds to the frequency of the incoming and outgoing waves from the body of water. The method of claim 27,
and continuously adjusting, using the control mechanism, a configuration of the at least one flow control device(s) in response to changes in frequency of incoming and outgoing waves. According to claim 28,
wherein, in use, the control mechanism selectively moves one or more of the flow control device(s) between the first configuration and the second configuration. According to claim 29,
The duct, the flow control device and the control mechanism are as defined in any one of claims 1 to 17. As a duct for accommodating the vibration column,
A. a first portion comprising a conduit arranged to be substantially submerged below the Mean Water Level (MSL) of a body of water in which it is in use and having an opening arranged to receive surging waves from said body of water; and
B. a second portion, further comprising another conduit suspended from the first portion and arranged to extend above the MSL when in use, for receiving water from surf after a wave has flowed through the first portion;
wherein the entry mouse at the opening of the first portion is arranged to extend partially above the MSL of the body of water in which it is positioned, in order to catch a larger flow of surging waves inward from the body of water. According to claim 31,
The first portion has a larger cross-sectional area at the opening than the rest of the first portion, and the conduit is provided with the entry mouse at the opening to accelerate the flow of the surf from the watershed to the duct. and wherein the cross-sectional area decreases when moving in a direction toward the second portion in the region. The method of claim 31 or 32,
wherein the uppermost and outermost regions of the entry mouth of the first portion are arranged to extend partially above the MSL of a body of water when in use. The method of any one of claims 31 to 33,
wherein the top surface of the first portion slopes downward when moving in a direction from the entry mouse at the opening toward the second portion. The method of any one of claims 33 to 36,
A duct as otherwise defined in any one of claims 1-19. A device for extracting energy from a vibrating working fluid, comprising:
- a housing defining a flow path for the working fluid;
- an energy conversion unit disposed in the housing and, when in use, in fluid communication with the working fluid in the flow passage; and
- in fluid communication with the flow path to selectively change the configuration of the flow path, in use, between an active configuration in which the working fluid acts on the energy conversion unit and a bypass configuration in which the working fluid bypasses the energy conversion unit; An apparatus comprising flow control means. 37. The method of claim 36,
wherein the flow control means and the energy conversion unit are configured to operate continuously so that, in use, a flow of the working fluid exits the flow passage through the flow control means and a flow of the working fluid enters the passage through the energy conversion unit; Device. 38. The method of claim 37,
wherein the housing is arranged to receive a frequency column positioned adjacent to the sea, and wherein the direction of the working fluid acting on the energy conversion unit is related to the fall of a wave passing therethrough. The method of any one of claims 36 to 38,
wherein the energy conversion unit comprises a turbine rotor. 40. The method of any one of claims 36 to 39,
18. A device as otherwise defined in any one of claims 2-17. A method of extracting energy from a vibrating working fluid comprising:
(i) positioning at least partially within a body of water having waves, a housing defining a flow path for receiving the vibratory working fluid;
(ii) arranging an energy conversion unit to be in fluid communication with the vibrational working fluid; and
(iii) a configuration of the flow path between an active configuration in which the working fluid acts on the energy conversion unit when flowing in a first set direction and a bypass configuration in which the working fluid bypasses the energy conversion unit when flowing in a second direction and providing flow control means for selectively changing . The method of claim 41 ,
A method as otherwise defined in any one of claims 28-30. A method for positioning an oscillating wave column energy capture device at an offshore location within a body of water comprising:
(i) positioning the device, which is itself equipped with a floating aid, on an operatively submersible floating platform;
(ii) causing the platform and the device to float on the body of water;
(iii) moving the platform and the device to a set position within the body of water;
(iv) submerging the platform and thus separating it from the device, thereby leaving the device afloat in the body of water by means of the flotation aid; and
(v) thereafter removing the flotation aid at the set position so that the device may be partially submerged and placed on the seabed of a body of water for intended operational use of the device. 44. The method of claim 43,
A method, wherein the energy harvesting device is otherwise as defined in any one of claims 1-17 or 36-40.

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